Here's a rare radio relay Porcelain Tramp insulator from the UK. This is a U-1900 that is rarely seen or offered. These saw limited use in England for an early TV cable network. This one has the scarce Bullers 1942 marking on the dome! NIA website only shows unmarked example.

Measures 3"x3". Has chip on reverse but displays great!

First email gets this rare tramp for only $175 plus 11 shipping. Thanks!